Retroperitoneoscopic Ureteronephrectomy for Crossed Renal Ectopia

Retro-peritoneal or trans-abdominal minimal-invasive access to the kidney is still debated. Authors describe an exceptional case of crossed-fused kidneys and explain the advantages of a retroperitoneoscopic approach in order to undergo an uretero-nephrectomy of the crossed kidney.

Retroperitoneoscopic surgery is the mini-invasive alternative of choice in order to approach retroperitoneal organs in children (1,2). We report a case of retroperitoneoscopic uretero-nephrectomy for crossed renal ectopia and discuss shortly why we choose the retroperitoneal way in comparison with the transperitoneal one.

Case Report

A five month old boy presented with abdominal pain. At interrogation we noted that prenatal ultrasound detected a right kidney agenesis. Abdominal ultrasound at the time of hospitalisation showed cystic masses at the lower pole of the left kidney, absence of right kidney and another solitary cystic mass (30mm) above the bladder. Voiding cystourethrography revealed grade I reflux into a left ureter. Cystoscopy showed 2 meatus. The right was medial; the left in a normal position. Retrograde ureteropyelography through the right meatus showed a blind ureter, a few cm long, going from right to left. The cystic mass above the bladder was not opacified during the exploration. Retroperitoneoscopic exploration of the left flank was decided after introducing of an ureteral catheter in the left ureter.

The patient was placed on a right lateral position and an open technique was used to create the space (fig. 1). After introduction of 2 operating trocars (3mm) exploration began (fig 2). A dysplastic “right” kidney was dissected from the lower pole of the left kidney. Clear demarcation of the 2 parenchymas was noted. Transsection was conducted using bipolar electrocautery without notable bleeding. The cystic masses were removed. The ureter was dissected by the same incision and the lower cystic mass, attached to the fibrotic ureter, was easily removed in the same way. The lower, larger part of the ureter was not closed in order to avoid eventual abscess formation. A postoperative urinoma occured, necessitating aspirative drainage for 3 days. At 1 month follow-up ultrasonography was normal with disappearance of all the cystic masses. The boy is well after more than 1 year follow-up.

Figure 1. Trocar position for a left kidney approach

Figure 2. Operative view of the open access to the kidney before introducing the first smooth trocar

Discussion

Laparoscopic nephrectomy of a crossed kidney was described some years ago (3). We preferred the retroperitoneal approach for several reasons. First, because it is the most natural to approach the kidney, even with a mini-invasive technique. Second, well known complications of a transperitoneal route, such as bowel and great vessel injury are avoided by this approach, but also other organs injuries (4). Third, dissection of the ureter by the same incision up to the bladder is possible (1, 2). It was of main interest in this particular case with a ureteral cystic dilatation just above the bladder. Fourth, operative time is probably less due to a more direct way. Fifth, the risk of post-operative adhesions formation, even decreased by laparoscopy, does not disappear (5). Sixth, in case of difficult dissection (for example accidental peritoneum opening and “gas leak” into the peritoneum), the peritoneum may be largely opened and the operation can be continued by a transperitoneal route after adapted trocar placement (6).

The main problem is creation of a working space. Some experience is needed. Perfect triangulation of the instruments is difficult to be obtained in such a limited space (fig 2). That makes suturing difficult, particularly in children under 2 years of age (2, 6). But suturing was, at least, not needed in this particular case report.

Conclusions

Crossed renal ectopia is a very rare condition. Most of the patients present with abdominal pain. Lumboscopy is a natural and direct mini-invasive approach to the kidney even in such exceptional cases. Vision is excellent due to magnification and absence of peritoneal intrusion avoids complications due to this approach. Cosmetic results are excellent and pain seems reduced in comparison with lumbotomy or laparoscopy (no shoulder pain). Consider only one day of hospitalisation.